Patent US3189053A successfully refreshed from Google Patents.
EP0276744A2
Expired / Lapsed
EP
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Synchronous rotation control system of magnetically recording disk
Assignee: Fujitsu Ltd
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Filing: 1988-01-20
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Granted: —
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Expires: 2008-01-20
Abstract
Abstract Magnetically recording disk apparatus including: means (4, 4a) for moving a magnetically reading/writing head (3, 3a) across spirally or coaxially provided recording cylinders (W1 to Wn) of the apparatus; index marks (IS1, IS2ʹ to ISnʹ), as indications of single disk-rotations, being magnetically written in respect of each cylinder (W1 to Wn), delayed from a reference angular position (MIX, RCP, RSP) for disk rotation, the index marks being positioned so as to be continuous between adjacent cylinders; and a servo control mechanism (5, 6) for synchronizing rotation of the disks (1, 1a) with a given synchronization pulse (RCP, RSP) by reading out the index marks (IS1, IS2ʹ to ISNʹ), further comprising: delay means (7) for delaying index signals (INDXP1 to INDXPn), read out from index marks (IS1, IS2ʹ to ISnʹ), such that the phase angle of the delayed index signals (DIDXP1 to DIDXPn), with respect to the reference angular position for disk rotation (MIX, RCP, RSP), is essentially constant regardless of the cylinders in respect of which the read out index signals are provided.
Inventors
- 👤 Toshifumi Fujitsu Limited Pat. Dept. Hatagami
- 👤 Masahito Fujitsu Limited Pat. Dept. Iwatsubo
- 👤 Tooru Fujitsu Limited Pat. Dept. Shinohara
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 06:11
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/48; G11B5/54; G11B5/55; G11B5/5521; G11B5/5526; G11B5/553; G11B5/5547; G11B19/00; G11B19/20; G11B19/28; G11B27/00; G11B27/10; G11B27/19; G11B27/28; G11B27/30; G11B27/3027
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
132 words
Magnetically recording disk apparatus including: means for moving a magnetically reading/writing head across spirally or coaxially provided recording cylinders of the apparatus; index marks, as indications of single disk-rotations, being magnetically written in respect of each cylinder, delayed from a reference angular position for disk rotation, the index marks being positioned so as to be continuous between adjacent cylinders; and a servo control mechanism for synchronizing rotation of the disks with a given synchronization pulse by reading out the index marks, further comprising: delay means for delaying index signals, read out from index marks, such that the phase angle of the delayed index signals, with respect to the reference angular position for disk rotation, is essentially constant regardless of the cylinders in respect of which the read out index signals are provided.
Claim 2
Dependent Claim
132 words
Magnetically recording disk apparatus including: means for moving a magnetically reading/writing head across spirally or coaxially provided recording cylinders of the apparatus; index marks, as indications of single disk-rotations, being magnetically written in respect of each cylinder, delayed from a reference angular position for disk rotation, the index marks being positioned so as to be continuous between adjacent cylinders; and a servo control mechanism for synchronizing rotation of the disks with a given synchronization pulse by reading out the index marks, further comprising: delay means for delaying index signals, read out from index marks, such that the phase angle of the delayed index signals, with respect to the reference angular position for disk rotation, is essentially constant regardless of the cylinders in respect of which the read out index signals are provided.
Claim 3
Dependent Claim
49 words
Apparatus according to claim 1, wherein the means for moving the magnetically reading/writing head comprises an arm which rotates in a plane parallel to a disk surface, in respect of which the head is provided, around an axis provided at an end of the arm opposite from the head.
Claim 4
Dependent Claim
73 words
Apparatus according to claim 1 or 2, wherein said delay means includes a digital counter which counts clock pulses input thereto, a number of clock pulses to be counted being predetermined depending on the cylinder at which the head is currently located, from which an index signal is read, and said counter enables the read index signal to be output as a delayed index signal when the counter finishes counting said predetermined number.
Claim 5
Dependent Claim
27 words
Apparatus according to claim 3, wherein the cylinders, from the innermost to the outermost are addressed by numbers of a simply increasing or a simply decreasing sequence.
Claim 6
Dependent Claim
33 words
Apparatus according to claim 4, wherein the number of clock pulses to be counted in relation to a particular cylinder is in essentially linear relationship to the cylinder address number of that cylinder.
Claim 7
Dependent Claim
60 words
Apparatus according to claim 1 or 3, wherein the numbers of clock pulses to be counted for different cylinders are stored in memory means in relationship to cylinder address numbers, the numbers of clock pulses to be counted being predetermined so that delayed index signals are generated at an essentially constant phase angle with respect to the reference angular position.
Claim 8
Dependent Claim
30 words
Apparatus according to claim 3, 4, 5 or 6, wherein the number of clock pulses to be counted for each cylinder is predetermined commonly for a group of neighboring cylinders.
Claim 9
Dependent Claim
39 words
Apparatus according to claim 3, 4, 5, 6 or 7, wherein clock pulse cycle time is chosen to be approximately an integral multiple of a difference of delay times between index marks written in respect of two neighboring cylinders.
Claim 10
Dependent Claim
35 words
Apparatus according to claim 7, wherein clock pulse cycle time is chosen to be approximately an integral multiple of a difference of delay times between index marks written in respect of two neighboring cylinder groups.
Claim 11
Dependent Claim
47 words
Apparatus according to claim 3, 4, 5, 6 or 7, wherein clock pulse cycle time is chosen to be an integral multiplication of approximately (a) the total sum of the deviations between index marks from adjacent cylinders divided by (b) the total number of cylinders minus one.
References Cited (Backward Citations)
No citation records indexed.
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